工字形铝合金偏心压杆平面内稳定承载力研究

In-Plane Stability Capacity of I-Section Aluminum Alloy Bars under Eccentric Compression

运用ANSYS软件对常用的铝合金挤压型材偏心压杆的平面内稳定承载力进行了研究,分析了不同长细比和偏心率杆件的稳定性能,并讨论了残余应力与初弯曲对杆件承载力的影响.研究结果表明:除相对偏心率很大及长细比很小的情况外,工字形截面偏心压杆受拉翼缘不会进入塑性状态;初弯曲对杆件的影响随长细比和弯矩的增大而减小;铝合金挤压型材残余应力峰值很小,对杆的承载力影响不大,可忽略不计.在大量数值分析的基础上,拟合出了工字形铝合金偏心压杆的平面内稳定计算公式,可供工程设计参考.

In-plane stability capacity of I-section aluminum alloy bars under eccentric compressions was investigated with FEA program of ANSYS. The stability of the bars with different slenderness ratio and eccentricity was analyzed and the influence of initial crookedness and residual stresses on the stability was emphatically discussed. The results show that the plastic extension would not occur in tensile region until eccentricity is large and slenderness ratio is small. Moreover, the influence of initial crookedness would be reduced as slenderness ratio and bending moment are increased. In addition, the influence of residual stresses can be neglected because the maximum residual stresses are small. Based on a large number of calculated data, a formula was presented for in-plane stability capacity of I-section aluminum alloy bars under eccentric compressions, which could be used for engineering design.